code: def test_mask_arg(self):
      # TODO
      pass
  
imports: import warnings
  import numpy
  import pytest
  from keras import backend
  from keras import layers
  from keras import testing
  from keras.layers.core.input_layer import Input
  from keras.layers.input_spec import InputSpec
  from keras.models import Functional
  from keras.models import Model
label_desc: Use image node_id 10 for calling the FunctionalTest obj's underlying member method code with example usage: obj.test_mask_arg() without return types